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Recycling technology for printed wiring boards (PWBs) with mounted electronic components was studied for the purpose of disassembling the boards, recovering useful materials, and reusing these materials. An automatic removal method was developed for the electronic components on the basis of a combination of heating to above the solder melting temperature and applying impacting the shearing forces. Most of the electronic components were recovered undamaged and the solder was able to be recovered as particles. The solder remaining on the board was recovered by abrading the board surface and by using a heating‐impacting process. After these processes, the resin board (a cured epoxy resin board reinforced with glass fibre)was pulverised and separated into a copper‐rich powder (copper: 82 Wt%) and a glass fibre and resin mixture powder (glass fibre‐resin powder) by gravimetric and electrostatic methods. The recovered electronic components, solder and copper‐rich powder were used as valuable metal resources for refining. Moreover, the recovered glass fibre‐resin powder was found to be a useful filler for plastic products such as epoxy resin and ABS (acrylonitrile/butadiene/styrene copolymer) resin.

Today, using lightweight structural concrete plays a major role in reducing the damage to concrete structures. On the other hand, lightweight concretes have lower compressive and flexural strengths with lower impact resistance compared to ordinary concretes. The aim of this study is to investigate the effect of simultaneous use of waste glass powder, microsilica and polypropylene fibers to make sustainable lightweight concrete that has high compressive and flexural strengths, ductility and impact resistance.

In this article, the lightweight structural concrete is studied to compensate for the lower strength of lightweight concrete. Also, considering the environmental aspects, microsilica as a partial replacement for cement, waste glass powder instead of some aggregates and polypropylene fibers are used. Microsilica was used at 8, 10 and 12 wt% of cement. Waste glass powder was added to 20, 25 and 30 wt% of aggregates, while fibers were used at 0.5, 1 and 1.5 wt% of cement.

After making the experimental specimens, compressive strength, flexural strength and impact resistance tests were performed. Ultimately, it was concluded that the best percentage of used microsilica and glass powder was equal to 10 and 25%, respectively. Furthermore, using 1.5 wt% of fibers could significantly improve the compressive and flexural strengths of lightweight concrete and increase its impact resistance at the same time. For constructing a five-story building, by replacing cement with microsilica by 10 wt%, the amount of used cement is reduced by 5 tons, consequently producing 4,752 kg less CO₂ that is a significant value for the environment.

The study provides a basis for making sustainable lightweight concrete with high strength against compressive, flexural and impact loads.

This purpose of this paper is to provide an overview of the steps and processes behind successfully adapting novel materials, namely virgin glass and recycled glass, to three‐dimensional printing (3DP).

The transition from 3DP ceramic systems to glass systems will be examined in detail, including the necessary modifications to binder systems and printing parameters. The authors present preliminary engineering data on shrinkage, porosity, and density as functions of peak firing temperature, and provide a brief introduction to the complexities faced in realizing an adequate and repeatable firing method for 3D printed glass.

Shrinkage behavior for the 3D printed recycled glass showed significant anisotropy, especially beyond peak firing temperatures of 730°C. The average shrinkage ratios for the slow‐ and fast‐axes to the Z‐axis were 1:1.37 and 1:2.74, respectively. These extreme differences can be attributed to the layer‐by‐layer production method and binder burn‐off. At 760°C, the apparent porosity reached a minimum of 0.36 percent, indicative of asymptotic behavior that approaches a fully dense 3DP glass specimen. At low firing temperatures, the bulk density was similar to water, but increased to a maximum of 2.41 g/cm³. This indicates that 3DP recycled glass can behave similarly to common glass with accepted published bulk densities ranging from 2.4‐2.8 g/cm³.

Heating schedule analysis and optimization may reduce geometric variations, therefore, the firing method should be investigated in greater depth.

This paper provides a guide to successfully adopting glass to commercially available 3DP hardware. This research has also enabled rapid prototyping of recycled glass, a monumental step towards a sustainable future for 3DP.

Currently, there is a great demand for those food products that are easy to prepare or ready for direct consumption. Making pear fruit/juice available round the year is desirous owing to pears' high-nutritional value and specific pleasant taste. Pear is, however, a seasonal fruit and under ambient conditions has a limited shelf life rendering it available as fresh fruit for a specific period.

The study aimed to optimize the spray drying process parameters using response surface methodology for the development of pear juice powder. The process variables included the inlet air temperature of 140–210°C, maltodextrin levels of 4–25%, atomization speed of 11,400–28,000 rpm, feed flow rate of 180–630 mL/hr, and feed total soluble solids (TSS) of 13–30°Brix. The dependent responses were powder yield, solubility, antioxidant activity {% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity}, dispersibility, hygroscopicity and particle density.

Among independent variables, inlet air temperature showed a predominant effect. The optimum processing conditions for the development of pear juice powder with optimum quality were 163.02°C inlet air temperature, 13.50% maltodextrin, 28,000 rpm atomization speed, 390.94 mL/h feed flow rate, and 25.5°Brix feed TSS. Under these optimum conditions, pear powder with desirable properties could be produced. The experimental and predicted values were found to be in agreement, indicating the suitability of the model in predicting optimizing responses of pear powder. Glass transition temperature of pear powder was found to be 36.60 ± 0.40°C, which is much higher than that of ambient temperature, suggesting better shelf stability.

The processing of pear fruit has resulted in the increased demand for pear juice powder in both domestic and international markets as a primer of new food products. The optimum conditions obtained in the current study could provide a new insight to the food industry in developing spray-dried pear powder of optimum quality. This can open up a new horizon in the field of food industry for the common masses of Jammu and Kashmir, India.

Apricots are not only nutritionally-rich but also possess pharmacological significance owing to their high antioxidant activity, and they are rich in vitamins, fibers, bioactive phytochemicals and minerals. Because of its immense organoleptic characteristics, apricot juice (AJ) is well accepted; however, it has a limited shelf-life, thereby demanding it to be converted into other shelf-stable form. One of the approaches is converting this juice into dehydrated powder. Amongst the various dehydration techniques available, spray drying is usually preferred; however, it involves the use of several independent variables, which need to be optimized, thus prompting to optimize the process to obtain spray dried apricot powder (SDAP) with improved quality.

The spray-drying process of apricot juice was done using the response surface approach. The process variables included the inlet air temperature of 135–220°C, gum arabic concentration of 4–25%, feed flow rate of 124–730 mL/h, feed total soluble solids (TSS) of 10-30°Brix and atomization speed of 11,400–28,000 rpm. The dependent responses were powder yield, hygroscopicity, solubility, moisture content, carotenoids (CT), ascorbic acid (AA), radical scavenging activity (RSA), lightness, wettability, bulk density, particle density and porosity.

Amongst all independent variables, inlet air temperature had most predominant impact on all the investigated responses. The optimum processing conditions for development of apricot powder with optimum quality were 190°C inlet air temperature, 18.99% gum arabic, 300.05 mL/h feed flow rate, 24°Brix feed TSS and 17433.41 rpm atomization speed. The experimental values were found to be in agreement with the predicted values, indicating the suitability of models in predicting optimizing responses of apricot powder. Flowability as Carr's index (CI) (22.36 ± 1.01%) suggests fair flow of powder. Glass transition temperature of powder was 57.85 ± 2.03°C, which is much higher than that of ambient, suggesting its better shelf stability.

To the best of author's knowledge, very limited or very few studies have been carried out on the spray-drying process for the manufacture of SDAP. The results of this investigation will open up new horizons in the field of food industry in the Union Territory of Jammu and Kashmir, India or elsewhere in the apricot-growing areas of India.

This paper aims to discuss the evaluation of the compressive and splitting tensile strength of concrete mixes containing different proportions of up to 20 per cent glass aggregate. Portions of sand in concretes with and without admixtures were replaced with measurements of glass aggregates.

“Glascrete” is a term used for concrete in which crushed glass is used as a substitute for all or part of the aggregates. Glass can be recycled many times without changing its properties, making it an ideal material in concrete. Overall, 144 cubes and 144 cylinders of glascretes were prepared with different admixtures and subjected to compressive and splitting tensile strength test.

A comparison with a 21-day control mix indicated that glass aggregates are replacing sand in concrete ranging from 5 to 20 per cent by volume, resulting in 3.8-10.6 per cent and 3.9-16.4 per cent fall in compressive and tensile strength, respectively. However, the use of mineral admixture improved the properties of the mixes at 3, 7, 14 and 21 days.

Cities worldwide are congested, and even those with the best waste-management system would have issues with waste disposal after the year 2030. Consequently, waste management is a current issue for cities all over the world.

This study aims to evaluate the physical properties of mortar mixes that contain different volumes of waste glass as substitutes for fine aggregate with or without additives. Mineral additives are used to improve the mechanical properties of glascrete mixes in addition to its chemical resistance by absorbing the OH⁻ ions responsible for the possible alkali-silica reaction (ASR). It also reduces the adverse effects of mix-dimensional stability. Water-reducing admixtures are used to reduce the impact of the ASR by minimizing the amount of moisture in concrete, in effect decreasing the possible expansion of any produced gel. In this research, compressive and splitting tensile strength of concrete mortar containing waste glass of limited substitutions is evaluated.

Copper substrates covered with ceramic insulating coating were tested for their ability to be used in thick film technology. The ceramic coating was prepared by screen printing from a dielectric composition containing special glass and aluminium oxide and was fired at 820°C–1,000°C. The electrical properties of the coatings studied included voltage breakdown, surface and bulk insulation resistance and dielectric constant. Resistor compositions designed for use on ceramic substrates were screen printed, as on the substrates mentioned, on alumina or ceramic‐coated steel substrates and fired up to the required temperatures (820–875°C). The resistivity and TCR of the prepared resistors were measured in relation to firing temperature. The distribution of lead, bismuth, ruthenium, barium, palladium, silver and copper in the system resistor (or conductor) ceramic coating/copper substrate was investigated. Reference was made to the application of ceramic coatings on copper in other fields, e.g., in heavy‐current electronics.

Rapid tooling (RT) integrated with additive manufacturing technologies have been implemented in various sectors of the RT industry in recent years with various kinds of prototype applications, especially in the development of new products. The purpose of this study is to analyze the current application trends of RT techniques in producing hybrid mold inserts.

The direct and indirect RT techniques discussed in this paper are aimed at developing a hybrid mold insert using metal epoxy composite (MEC) in increasing the speed of tooling development and performance. An extensive review of the suitable development approach of hybrid mold inserts, material preparation and filler effect on physical and mechanical properties has been conducted.

Latest research studies indicate that it is possible to develop a hybrid material through the combination of different shapes/sizes of filler particles and it is expected to improve the compressive strength, thermal conductivity and consequently increasing the hybrid mold performance (cooling time and a number of molding cycles).

The number of research studies on RT for hybrid mold inserts is still lacking as compared to research studies on conventional manufacturing technology. One of the significant limitations is on the ways to improve physical and mechanical properties due to the limited type, size and shape of materials that are currently available.

This review presents the related information and highlights the current gaps related to this field of study. In addition, it appraises the new formulation of MEC materials for the hybrid mold inserts in injection molding application and RT for non-metal products.

So far as the various British Food and Drugs Acts are concerned, the meaning of “sophistication” or “adulteration,” which includes “substitution,” is now very wide.

This paper aims to present a method for the reduction of dielectric constant of low-temperature co-fired ceramics (LTCC) substrates with the use of controlled internal porosity.

A glass-ceramic green tape with addition of graphite as a pore former was developed. The green tapes were laminated and then sintered into multilayer structures with porous interior and thin external dense layers. Microstructure of green and fired structures was studied using optical and scanning microscopy. The behavior of the samples during heating was examined in a heating microscope. Impedance spectroscopy was applied for investigation of dielectric properties of the fabricated substrates.

Microstructure and dielectric properties of the fabricated LTCC structures were compared with the characteristics for non-porous samples with the similar composition. Introduction of 50 Wt.% admixture of graphite in the internal layers of the LTCC substrate was found to result in decrease in dielectric constant value down to about 3. Application of non-porous outer layers improved mechanical strength of the structure and smoothness of its surface, allowing screen printing of conductive pastes on both sides of the substrate.

The rapid growth of the wireless communication industry has created a great demand for the development of new and improved materials and devices operating properly at high frequencies. The fabricated materials can be useful for substrates of microwave devices.

The paper presents an innovative method of dielectric constant decrease of substrate materials. Getting insight into the phenomena responsible for formation of pores is crucial for designing materials for microwave electronics.